Darchei Emori

Vayikra (18:3) After the doings of the land of Egypt, where you dwelt, shall you not do; and after the doings of the land of Canaan, where I bring you, shall you not do; nor shall you walk in their ordinances.

Shabbos (67a) Whatever is used as a remedy is not forbidden on account of the ways of the Amorite.

Beis Yosef (Y.D. 178) the expression "the ways of the Emorite" contains two prohibitions. 1) prohibition against sorcery, 2)the other is the general prohibition for Jews to imitate without good cause the other nations.

Pesachim (25a) We may cure ourselves with all things, save with the wood of the asherah. How is it meant? If we say that there is danger, even the wood of the asherah too [is permitted]; while if there is no danger, even all other forbidden things of the Torah too are not permitted? — After all it means that there is danger, yet even so the wood of the asherah must not be used.

Rabbeinu Yona (Shaarei Tshuva 03 104) In their practises do not go – we are being warned by this  to stay far away from darchei Emori as well as incantations or amulets which have not been shown to work for  medical problems

Rambam (Moreh Nevuchim 3:37) In order that we may keep far from all kinds of witchcraft, we are warned not to adopt any of the practices of the idolaters, even such as are connected with agriculture, the keeping of cattle, and similar work. The Law prohibitseverything that the idolaters, according to their doctrine, and contrary to reason, consider as being useful and acting in the manner of certain mysterious forces. . Our Sages call such acts "the ways of the Amorite"; they are kinds of witchcraft, because they are not arrived at by reason, but are similar to the performances of witchcraft, which is necessarily connected with the influences of the stars; thus "the manners of the nations" lead people to extol, worship, and praise the stare. Our Sages say distinctly, "whatever is used as medicine" does not come under the law of "the ways of the Amorite"; for they hold that only such cures as are recommended by reason are permitted, and other cures are prohibited. 

Rambam (Moreh Nevuchim 3:37) When a tree that casts off its fruit may be laden with stone or dyed with red colour, the following objection was raised: The loading of the tree with stones may be justified on the plea that it serves to weaken the strength of the tree, but why should it be permitted to dye the tree with red colour? This question shows that the dyeing of the tree with red colour, and all similar things which are not explained by analogy from nature, are prohibited as "ways of the Amorite." For the same reason our Sages said, "The uterus of animals which have been selected for the Sanctuary must be buried; it must not be suspended from a tree, and not buried in the cross-road, because this is one of 'the ways of the Amorite.'" 

Rambam (Moreh Nevuchim 3:37) It is not inconsistent that a nail of the gallows and the tooth of a fox have been permitted to be used as cures: for these things have been considered in those days as facts established by experiment. They served as cures, in the same manner as the hanging of the peony over a person subject to epileptic fits, or the application of a dog's refuse to the swellings of the throat, and of the vapours of vinegar and marcasite to the swelling of hard tumours. For the Law permits as medicine everything that has been verified by experiment, although it cannot be explained by analogy. 

Rambam (Shabbos 19:13) One may go out with a twig in his teeth or in his shoe to the public domain. But if it falls out, he should not replace it. And with padding or a sponge over a wound, so long as he does not tie a string or a cord over it. For a string and a cord have a distinct importance to him and are not useful for the wound. And he may go out with a garlic peel or an onion peel upon a wound or a dressing on top of a wound, and he may tie it and untie it on Shabbos. And with a bandage or an emollient or a plaster on top of a wound; and with a coin on top of a callus, and with a locust's egg, a fox's tooth and the nail of one crucified (which were understood to have medicinal properties). And with anything that we drape for healing—and that is when the physicians say it is useful. 

Sefer HaChinuch (511:2) Anyone who is a judge needs to know the wisdom of magic so that he will be able to distinguish about an act that is done, whether it is one of the types of magic or perhaps from the things done through the power of nature and in permissible ways. Anything that contains an element of healing does not contain the prohibition on account of the ways of the Amorite." 

Shabbos (67a) A tanna recited the chapter of Amorite practices before R. Hiyya b. Abin. Said he to him: All these are forbidden as Amorite practices, save the following: If one has a bone in his throat, he may bring of that kind, place it on his head, and say thus: ‘One by one go down, swallow, go down one by one’: this is not considered the ways of the Amorite. For a fish bone he should say thus: ‘Thou art stuck in like a pin, thou art locked up as within a cuirass; go down, go down.’ He who says, ‘Be lucky, my luck gad gedi and tire not by day or night,’ is guilty of Amorite practices. R. Judah said: Gad is none other but an idolatrous term, for it is said, ye that prepare a table for Gad. 

Shabbos (67a) If husband and wife exchange their names, they are guilty of Amorite practices. To say, ‘Be strong, o ye Barrels’! is forbidden as the ways of the Amorite. R. Judah said: Barrel is none other but the designation of an idol, for it is said, They that swear by the sin, of Samaria, and say, As thy god Dan liveth. He who says to a raven, ‘Scream,’ and to a she-raven, ‘Screech, and return me thy tuft for my good,’ is guilty of Amorite practices. He who says, ‘Kill this cock, because it crowed in the evening,’ or, ‘this fowl, because it crowed like a cock,’ is guilty of Amorite practices. He who says. ‘I will drink and leave over, I will drink and leave over,’ is guilty of the ways of the Amorite. He who breaks eggs on a wall in front of fledglings, is guilty of Amorite practices. He who stirs eggs? before fledglings is guilty of Amorite practices. He who dances and counts seventy-one fledglings in order that they should not die, is guilty of Amorite practices. He who dances for kutah, or imposes silence for lentils, or cries for beans, is guilty of Amorite practices. She who urinates before her pot in order that it should be quickly cooked is guilty of Amorite practices. Yet one may place a chip of a mulberry tree and broken pieces of glass in a pot in order that it should boil quickly. But the Sages forbade broken pieces of glass to be employed thus on account of danger. Our Rabbis taught: A lump of salt may be placed in a lamp in order that it should burn brightly; and mud and clay may be placed under a lamp in order that it should burn slowly.   R. Zutra said: He who covers an oil lamp or uncovers a naphtha [lamp] infringes the prohibition of wasteful destruction. ‘Wine and health to the mouth of our teachers!’ is not considered the ways of the Amorite. It once happened that R. Akiba made a banquet for his son and over every glass of liquor that he brought he exclaimed, ‘Wine and health to the mouth of our teachers; health and wine to the mouths of our teachers and their disciples!’

Shulchan Aruch (O.C. 301:27) 27. It is permitted to go out on Shabbos with: a) the egg of a species of grasshopper known as a chargol (hung over one’s ear to relieve an earache); b) the tooth of a live fox (hung on a person who sleeps excessively); c) the tooth of a dead fox (hung on someone suffering from insomnia); and/or d) a nail from a wooden beam on which someone was crucified (used to heal a swelling that stems from a blow from [an] iron [implement]), whether it is during the week or during Shabbos. Doing so is not considered as following the ways of the Amorites. So too, with anything that is used for healing. However, if one makes something that is not recognized as something used for healing, it is forbidden because this is considered as following the ways of the Amorites. However, any incantation is permitted and not forbidden except for those that are checked and do not heal. And there are those who worry for this regarding every amulet that is not effective because it is following the ways of the Amorites. 

Melamed Lhoil (2 63:1) Question: Should there be protest against the widespread custom of hanging charms in the room of a new mother Answer These are amulets. They are beneficial even for those who don’t believe in them and should not arouse objections since the rule is that whatever is done for health does not violate the prohibition of darchei Emori.  

Rabbeinu Yona (Shaarei Tshuva 03 104) In their practices do not go – we are being warned by this  to stay far away from darchei Emori as well as incantations or amulets which have not been shown to work for  medical problems

Igros Moshe (OH V #18.27) It is obvious that according  to “some say” opinion that an amulet which has not been verified to work is prohibited not only on Shabbos but also during the week because of the prohibition of Darchei Emori. It is not comparable to an unverified Amulet on Shabbos where it is sufficient to use it if it cures on three occasions to remove the prohibition of Darchei Emori. Also for Shabbos it needs to be verified to work for that person or that Amulet.